Global navigation satellite systems (GNSS) may be broadly defined to include GPS (U.S.), Galileo (proposed), GLONASS (Russia), Beidou (China), IRNSS (India, proposed), QZSS (Japan, proposed) and other current and future positioning technologies using signals from satellites, with or without augmentation from terrestrial sources. Information from GNSS may be increasingly used for computing a user's positional information (e.g., a location, a speed, a direction of travel, etc.).
Pursuant to an exemplary scenario, in GNSS, multiple satellites may be present, with each transmitting a GNSS satellite signal. A received signal at a GNSS receiver contains one or more of the transmitted GNSS satellite signals. In order to obtain the information from the respective transmitted signals, the GNSS receiver performs a signal acquisition/tracking procedure. More specifically, the GNSS receiver searches for the corresponding transmitted signals in the received signal and then locks onto them so as to subsequently track the corresponding satellites to receive the satellite information.
Furthermore, in accordance with one exemplary scenario, the signal acquisition/tracking procedure may entail correlating the received signal (which may be, for example, down-converted to baseband) with a local signal generated within the GNSS receiver for various estimates of Doppler frequencies. The correlation results are coherently and non-coherently accumulated for detecting and acquiring satellite signals. The memory/area requirement associated with such accumulation increases sizably with an increase in the number of searches (Doppler/GNSS satellite combinations) performed during correlation.